Professional Graphite Electrodes & allied graphite product Supplier

How to Distinguish the Quality of Graphite Surface Processing

1. Flexural Strength of materials
The flexural strength of the material is a direct embodiment of the strength of the material, showing the tightness of the internal structure of the material. High strength material, its discharge performance is relatively good, for the high accuracy of the electrode, as far as possible to choose the better strength of the material. For example: TTK-4 can meet the general requirements of electronic connectors mold, but some have a special precision of the electronic connector mold, you can choose the same size, but the strength of a slightly higher material TTK-5 material.
2. Shore hardness of materials
In the subconscious understanding of graphite, graphite is generally considered as a softer material. However, the actual test data and application shows that graphite hardness is higher than metal material. In the special graphite industry, the common hardness test standard is the shore hardness measurement method, its test principle and the metal test principle is different. Because of the graphite's layered structure, it has very advantageous cutting performance in the cutting process, the cutting force is only about 1/3 of the copper material, the machined surface is easy to be treated.
However, because of its high hardness, in cutting, the loss of the tool will be slightly greater than the cutting metal tool. At the same time, the high hardness of the material in the discharge loss control is relatively excellent. In our EDM materials system, for the application of more than the same size of materials have two of materials to choose from, a slightly higher hardness, a slightly lower hardness to meet a variety of different requirements of the customer's needs. Such as: The average particle size of 5μm materials, there are ISO-63 and TTK-50, the average particle size of 4μm materials, TTK-4 and TTK-5, the average size of the 2μm material, TTK-8 and TTK-9. The main consideration is to consider the different types of customers for the discharge and machining of the biased direction.
3. Average particle diameter of material
The average particle diameter of the material directly affects the discharge condition of the material. The smaller the average particle, the more uniform the discharge, the more stable the discharge condition, the better the quality of the material.
For the surface, precision requirements of the forging, die-casting mold, usually recommended the use of coarse particles of materials, such as ISEM-3, etc. for the surface, the accuracy of the high requirements of the electronic mold, the use of the average particle diameter in the 4μm of the following materials, to ensure that the precision of the machined die The smaller the average particle size of the material, the smaller the loss of the material, the greater the force between the ionic groups. For example: generally recommended in precision die-casting molds, forging molds, ISEM-7 is enough to meet the requirements; But customers with high accuracy requirements, recommend the use of TTK-50 or ISO-63 materials to ensure a smaller material loss, thus ensuring the precision and surface roughness of the mold.
At the same time, the larger the particles, the faster the discharge speed, the less the loss of roughing. The current intensity of the discharge process is different, which causes the energy of the discharge to differ. But the surface finish after discharge also changes with the particle.
4. Intrinsic resistivity of materials
According to the characteristic statistics of the material, if the average particle of the material is the same, the discharge rate of the resistivity is much slower than the resistivity is small. For materials with the same average particle size, the strength and hardness of the material with small resistivity are slightly lower than that of the resistivity material. That is, the speed and loss of the discharge will be different. Therefore, it is very important to choose the material according to the actual application.
Because of the particularity of powder metallurgy, there is a certain fluctuation range for each parameter of the batch material to have the representative value of the material. But the same grade of graphite material, its discharge effect is very close, due to various parameters caused by the application of the difference is very small.